Nutritionists Recommend Eating More “Slow Carbs”—What Does This Mean for Your Diet?

The Science behind fad diets

By The Great Courses Staff

Nutritionists’ recommendations for healthy diets have changed significantly over the last 20 to 30 years. As scientific and medical studies advance, doctors have suggested diets that cut out fats and carbohydrates. However, new research suggests that a viable alternative isn’t an across-the-board reduction of carbs, but a careful selective process of specific kinds of carbs to keep us feeling full and fit.

foods that are high in carbohydrates

Recent discoveries have suggested whole-kernel grains that undergo a minimum of food processing may be a key item in a healthy diet. Minimally processed whole grains take longer to digest and stay in the stomach for longer periods of time. Thus, this leads to a slower and gentler rising of blood sugar as well as making us feel fuller for longer.

Maintaining a proper level of carbohydrate intake is essential to a healthy dietary regimen. The body prefers glucose from carbs as its fuel source over proteins and fat, but too much leads to major health problems. “Most scientists agree that the U.S. is an over-carbed nation,” said Dr. Michael Ormsbee, Associate Professor in the Department of Nutrition, Food and Exercise Sciences and Interim Director of the Institute of Sports Sciences and Medicine in the College of Human Sciences at Florida State University.

In light of this information, millions of Americans a year are encouraged to readjust their carbohydrate intake. With a smaller amount of glucose being produced to fuel the body, our energy must come from different sources.  “Fortunately, when you eat very little carbohydrates, you can still function from the production of ketones, which are simply a byproduct of excessive fat breakdown as a result of a low-carb diet,” Dr. Ormsbee said. “This excess fat breakdown is called ketosis.”

Unfortunately, going overboard with eliminating carbs from one’s diet can lead to health problems, too. “The research is quite clear that some glucose is required for life, and even more is likely needed if you decide to become extremely active,” Dr. Ormsbee said.

Carbohydrates are classified by their molecular structure. Monosaccharides, disaccharides, oligosaccharides and polysaccharides are the terms given to carbohydrates with one, two, three to nine, and 10 or more sugar molecules grouped together, respectively. The longer the carbohydrate chain, the slower the breakdown process. In turn, slower breakdowns lead to subtler variations in blood sugar and insulin levels. One such healthy food type is fibers, which includes bananas, oatmeal and dark leafy greens. According to Dr. Ormsbee, eating 14 grams of fiber per 1,000 calories can help lower blood cholesterol and blood fat levels.

“What’s important to understand is that our bodies work best for us when blood glucose remains at a constant level without large fluctuations throughout the day,” Dr. Ormsbee said. “When blood sugar is elevated for a prolonged period of time, numerous detrimental health and body composition outcomes can occur.” Furthermore, extended high blood glucose levels also mean higher levels of insulin, the hormone that inhibits fat breakdown and is intrinsically linked with diabetes.

Refined carbohydrates like cereal, candy and soft drinks have the most potential to cause negative effects to our health. Unprocessed carbs like vegetables and other foods with no added sugar can help us stabilize our glucose and insulin levels and make us feel full for longer. Contrary to an absolute avoidance of carbs, the suggested careful selection of slow-burning carbohydrates can form an important foundation of a healthy diet and a healthy life.

Dr. Michael Ormsbee contributed to this article. He is an Associate Professor in the Department of Nutrition, Food, and Exercise Sciences and Interim Director of the Institute of Sports Sciences and Medicine in the College of Human Sciences at Florida State University. He received his B.S. in Exercise Science from Skidmore College, his M.S. in Exercise Physiology (research emphasis in Sports Nutrition) from South Dakota State University, and his Ph.D. in Bioenergetics from East Carolina University.